如何通过condition max left join and select，然后选择另一个字段？

Question

数据库：SAP HANA

如何通过条件max左连接和select，然后选择另一个字段？

一个

user	no	qty
A	10	20
A	11	30
B	12	40
B	13	10

B

id	user
1	A
2	B

预期结果

id	user	no
1	A	11
2	B	12

有没有sql喜欢

select B.id, B.user, MAX(qty).NO
from B
left join A
on A.user = B.user

Answer 1

您可以使用以下方法实现此目的：

SELECT
    B.id,
    B.user,
    C.max_qty_no
FROM
    B
LEFT JOIN (
    SELECT 
        A.user,
        CASE
            WHEN A.qty = (
              MAX(A.qty) OVER (PARTITION BY A.user)
            ) THEN A.no
        END as max_qty_no
    FROM
        A
) C ON C.user = B.user AND
       C.max_qty_no IS NOT NULL;

或

SELECT
    B.id,
    B.user,
    C.max_qty_no
FROM
    B
LEFT JOIN (
    SELECT 
        A.user,
        REPLACE(
            MAX(CONCAT(A.qty,'-',A.no)),
            MAX(CONCAT(A.qty,'-')),''
                        
        ) as max_qty_no
    FROM
        A
    GROUP BY 
       A.user
) C ON C.user = B.user;

让我知道这是否适合你.

如何通过condition max left join and select，然后选择另一个字段？

How to left join and select by condition max, then choose another field?

sql

hana